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Alternative names
Direct immunofluorescence; E-rosetting; T and B lymphocyte assays; B and T lymphocyte assaysDefinition Return to top
A test that makes a quantitative measurement of T and B lymphocytes in the blood.How the test is performed Return to top
Blood is drawn from a vein, usually from the inside of the elbow or the back of the hand. The puncture site is cleaned with antiseptic, and an elastic band is placed around the upper arm to cause the vein to swell with blood.
A needle is inserted into the vein, and the blood is collected in air-tight vials or a syringe. During the procedure, the band is removed to restore circulation. Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.
Blood could also be obtained by capillary sample (fingerstick, or heelstick in infants).
After the blood is drawn it goes through a two step process. First, the lymphocytes are separated from other blood elements. Once the cells are separated, identifiers are added to distinguish between T and B lymphocytes. The E-rosetting test identifies T cells and direct immunofluorescence is used to identify B cells.
How to prepare for the test Return to top
No alteration in diet is necessary for this test.How the test will feel Return to top
When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.Why the test is performed Return to top
This test is performed to aid your health care provider in the diagnosis of immunodeficiency diseases. It may also be used to distinguish between benign and malignant lymphocytic disease. Finally, this test may be performed to monitor your response to therapy.Normal Values Return to top
Values vary from laboratory to laboratory, and depend on testing technique, but typically, T cells comprise 68% to 75% of total lymphocytes and B cells 10% to 20%.What abnormal results mean Return to top
Abnormal T and B cell counts suggest possible diseases. Further testing is indicated to confirm any of the suggested diagnosis.What the risks are Return to top
Risks associated with venipuncture are slight:Special considerations Return to top
Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others. Update Date: 11/3/2003 Updated by: Sherry Woodhouse, M.D., Department of Pathology and Laboratory Medicine, Cleveland Clinic Florida, Weston, FL. Review provided by VeriMed Healthcare Network.
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Page last updated: 28 October 2004 |